On the first schematic at the bottom where it says "See Fig B-22 " go to the last schematic that shows the lights. Book says connector 257 is under the Left Side Cover and you found connector 7 under the seat on top of the fender. If you check the signal from the TSSM or brake relay before the added components you can tell if the problem is with the flasher and anything else added. For example if nothing is connected between 257 and 7 then at 7A if you turn on the Left turn signal the V wire at position 3 should pulse 12V. to ground, all other wires should be 0. Hit the Brake r/y will show steady 12V. Not sure if front turns might be in mix or not.
Good luck

Blue box looks like a Custom Dynamics Signal Stabilizer and the red box looks like a Smart Tripple Play unit from CD as well. If you just disconnect the tripple play from the harness and the stabilizer and plug the stabilizer into the harness, check to see what you get. I would bet it is the tripple play that is frazzled.

Removed the flasher from loop & turn signals work properly (off until you activate), no more clicking in relay when hitting brake & no more flashing (obviously). I’m guessing time to open up the clam shell again & this time actually remove front brake switch from loop?

That would be a good place to start if you have had it open recently but check the rear first just in case...ya never know, and it only takes a second to pull off that plug and see if the lights go out.

Ok, latest update...
Didn’t call CD today, will try tomorrow if we still haven’t figured it out.
With flasher out of loop, brake light still on, blinkers off. Relay clicks when hit front switch, but not when I hit rear switch. Disconnect rear switch & no change. Opened clam shell, but haven’t gotten switched out of housing yet & trying not to just start cutting wires. R/Y has 12v constant with ignition on.